1. Field of the Invention
This invention relates to a vehicle dashmat with an air distribution system. In one of its aspect, the invention relates to HVAC air distribution systems for a vehicle. In another of its aspects, the invention relates to a dashmat incorporating an air distribution for directing conditioned air for the HVAC system throughout a vehicle passenger compartment.
2. Description of the Related Art
Virtually all contemporary vehicles include a heating, vent, and air conditioning (xe2x80x9cHVACxe2x80x9d) system for providing and distributing conditioned air throughout the interior of a vehicle passenger compartment. The conditioned air is generally distributed throughout the passenger compartment by an air distribution system, which typically comprises multiple channels or ducts fluidly connecting various portions of the passenger compartment interior with the conditioned air source, such as a heater, air conditioner, or exterior air. It is common to place a vent with or without adjustable louvers at the end of a fluid channel to control the direction of flow of the conditioned air from the distribution channel.
Initially, most vehicles limited the distribution channels within the confines of the vehicle dashboard and emit the conditioned air into the front seat area of the passenger compartment. There is a current trend, especially in larger vehicles, to provide distribution channels that extend into the rear seat of the vehicle passenger compartment to provide for a more even air distribution throughout the passenger compartment.
The increase in the number of distribution channels within the interior of the passenger compartment negatively impacts the usable volume of the passenger compartment, which is highly undesirable given the high value placed on passenger compartment volume by manufacturers and consumers. Additionally, the distribution channels can often result in unusual shapes to the passenger compartment interior because of the need to provide the distribution channels above the vehicle floor, such as in a console or the like. The addition of a distribution system structure to the interior of the passenger compartment also reduces the usable volume in combination with reducing the functionality of the available passenger compartment volume because of interference with passenger movement. Therefore, it is highly desirable to provide an air distribution system that minimizes the reduction of the available passenger compartment volume while permitting air distribution throughout the passenger compartment.
Current air distribution systems are also plagued by an additional problem in that almost without exception all sources of conditioned air are contained within the vehicle engine compartment, which is separated from the passenger compartment by a firewall, which is typically covered by a dashmat to reduce the sound passing from the engine compartment into the passenger compartment. The physical separation from the conditioned air sources and the air distribution system requires a fluid connection extending through the firewall and the dashmat, which requires the construction of openings through the dashmat that can reduce the dashmat""s performance by permitting the transfer of sound from the engine compartment into the passenger compartment through openings in the dashmat and/or through the fluid conduit itself. Therefore, it is highly desirable to have an air distribution system that does not adversely impact the sound absorbing function of the dashmat.
The invention relates to a dashmat for use in a vehicle passenger compartment comprising a firewall separating the passenger compartment from an engine compartment and a floorboard extending rearwardly from the firewall. The dashmat comprises a decoupling layer shaped to span the width of the vehicle passenger compartment and typically has a barrier layer. The decoupling layer has a lower surface adapted to abut the firewall and floorboard, and an upper surface adapted to face an interior of the passenger compartment. According to the invention, a header is formed in a front portion of the decoupling layer and is adapted to connect to a supply duct from a vehicle HVAC system. An air distribution channel is formed in the decoupling layer and extends rearwardly from the header through a substantial portion of the decoupling layer for distribution of conditioned air from the header throughout at least a front portion of the vehicle passenger compartment.
The dashmat typically includes a cover closing the air distribution channel. The cover is preferably a barrier layer or, optionally, a carpet positioned on the upper surface of the decoupling layer. Alternatively, the carpet can be used in combination with the barrier layer by placing the carpet on top of the barrier layer. The barrier layer is preferably made from a filled elastomeric material that has sound deadening qualities.
The decoupling layer is preferably molded from foam for dampening vibrations passing through or associated with the firewall. The header and the distribution channel can each be formed by a reduced thickness portion of the decoupling layer.
Vents can be formed in the decoupling layer for directing the flow of conditioned air from the channel into the vehicle passenger compartment. Preferably, a cover overlies and closes the air distribution channel. The cover can have multiple through openings fluidly connecting the channel to the vehicle passenger compartment to define the vents. The multiple through openings each comprise a set of perforations, which are preferably spaced relative to each other.
The cover can be a carpet or a barrier layer positioned on the upper surface of the decoupling layer. The barrier layer is preferably made from a material, such as a dense elastomer, to retard the transfer of sound from the firewall and floorboard into the vehicle passenger compartment.
In another embodiment, the invention relates to a dashmat in combination with a vehicle passenger compartment comprising a firewall separating the passenger compartment from an engine compartment and a floorboard extending rearwardly from the firewall. The dashmat comprises a decoupling layer spanning the width of the vehicle passenger compartment and having a lower surface and upper surface. The lower surface abuts the firewall and the floorboard and the upper surface faces the interior of the passenger compartment. According to the invention, a header is formed in a front portion of the decoupling layer and connects to a HVAC supply duct outlet in the firewall. An air distribution channel is formed in the decoupling layer and extends rearwardly from the header through a substantial portion of the decoupling layer for distribution of conditioned air from the header throughout at least a front portion of the vehicle passenger compartment.